Quarter wave light splitting

ABSTRACT

Embodiments of the present disclosure provide methods for producing images on substrates. The method includes providing a p-polarization beam to a first mirror cube having a first digital micromirror device (DMD), providing an s-polarization beam to a second mirror cube having a second DMD, and reflecting the p-polarization beam off the first DMD and reflecting the s-polarization beam off the second DMD such that the p-polarization beam and the s-polarization beam are reflected towards a light altering device configured to produce a plurality of superimposed images on the substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.15/207,991, filed on Jul. 12, 2016, which claims priority to U.S.Provisional Appl. No. 62/191,915, filed Jul. 13, 2015, which are herebyincorporated by reference in their entirety.

BACKGROUND Field

Embodiments of the present disclosure generally relate to methods forproducing an image on a substrate, and more particularly to methods forproducing an image on a substrate having twice the number of pixels as aconventional method.

Description of the Related Art

Photolithography is widely used in the manufacturing of semiconductordevices and display devices, such as liquid crystal displays (LCDs).Large area substrates are often utilized in the manufacture of LCDs.LCDs, or flat panels, are commonly used for active matrix displays, suchas computers, touch panel devices, personal digital assistants (PDAs),cell phones, television monitors, and the like. Generally, flat panelsmay include a layer of liquid crystal material forming pixels sandwichedbetween two plates. When power from the power supply is applied acrossthe liquid crystal material, an amount of light passing through theliquid crystal material may be controlled at pixel locations enablingimages to be generated.

Microlithography techniques are generally employed to create electricalfeatures incorporated as part of the liquid crystal material forming thepixels. According to this technique, a light-sensitive photoresist istypically applied to at least one surface of the substrate. Then, apattern generator exposes selected areas of the light-sensitivephotoresist as part of a pattern with light to cause chemical changes tothe photoresist in the selective areas to prepare these selective areasfor subsequent material removal and/or material addition processes tocreate the electrical features.

In order to continue to provide display devices and other devices toconsumers at the prices demanded by consumers, new apparatuses,approaches, and systems are needed to precisely and cost-effectivelycreate patterns on substrates, such as large area substrates.

As the foregoing illustrates, there is a continual need for an improvedtechnique for precisely and cost-effectively creating patterns on asubstrate.

SUMMARY

In one embodiment, a method for producing an image on a substrate isdisclosed herein. The method includes providing a single beam of lightto a multiple digital micromirror device (DMD) assembly, splitting thesingle beam of light into an s-polarization beam and a p-polarizationbeam, and reflecting the s-polarization beam and the p-polarization beamthrough the multiple DMD assembly such that the multiple DMD assemblyproduces a plurality of superimposed images on the substrate.

In another embodiment, a method for producing an image on a substrate isdisclosed herein. The method includes providing a p-polarization beam toa first mirror cube having a first DMD, providing an s-polarization beamto a second mirror cube having a second DMD, and reflecting thep-polarization beam off the first DMD and reflecting the s-polarizationbeam off the second DMD such that the p-polarization beam and thes-polarization beam are reflected towards a light altering deviceconfigured to produce a plurality of superimposed images on thesubstrate.

In one embodiment, an image projection system is disclosed herein. Theimage projection system includes at least one light source and amultiple DMD assembly. The multiple DMD assembly is configured toproduct a plurality of superimposed images from the light source. Themultiple DMD assembly includes a plurality of DMDs and a light alteringdevice configured to alter the light provided from the light source.

DETAILED DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 illustrates a perspective view of a processing system, accordingto one embodiment.

FIG. 2 illustrates a cross-sectional side view of the processing systemof FIG. 1, according to one embodiment.

FIG. 3 illustrates a perspective view of a plurality of image projectionsystems, according to one embodiment.

FIG. 4 illustrates a perspective schematic view of one image projectionsystem of the plurality of image projection systems of FIG. 3.

FIG. 5 illustrates a perspective view of a multiple DMD assembly,according to one embodiment.

FIG. 6 illustrates a method of producing an image on a substrate usingthe multiple DMD assembly of FIG. 5, according to one embodiment.

FIG. 7 illustrates another embodiment of a multiple DMD assembly.

FIG. 8 illustrates a method of producing an image on a substrate usingthe multiple DMD assembly of FIG. 7.

FIG. 9 illustrates an image projection system, according to anotherembodiment.

FIG. 10 illustrates a method of producing an image on a substrate usingthe image projection system of FIG. 9.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

It is to be noted, however, that the appended drawings illustrate onlyexemplary embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

DETAILED DESCRIPTION

Embodiments of the present disclosure generally relate image projectionsystems and methods for producing images on substrates. FIG. 1 is aperspective view of a system 100 that may benefit from embodimentsdisclosed herein. The system 100 includes a base frame 110, a slab 120,two or more stages 130, and a processing apparatus 160. The base frame110 may rest on the floor of a fabrication facility and may support theslab 120. Passive air isolators 112 may be positioned between the baseframe 110 and the slab 120 to reduce transmissions of vibrationstherebetween. The slab 120 may be a monolithic piece of granite, and thetwo or more stages 130 may be disposed on the slab 120. A substrate 140may be supported by each of the two or more stages 130. A plurality ofholes (not shown) may be formed in the stage 130 for allowing aplurality of lift pins (not shown) to extend therethrough. The lift pinsmay rise to an extended position to receive the substrate 140, such asfrom a transfer robot (not shown). The transfer robot may position thesubstrate 140 on the lift pins, and the lift pins may thereafter lowerthe substrate 140 onto the stage 130.

The substrate 140 may, for example, be made of quartz and be used aspart of a flat panel display. In some embodiments, the substrate 140 maybe made of other materials. In some embodiments, the substrate 140 mayhave a photoresist layer formed thereon. A photoresist is sensitive toradiation and may be a positive photoresist or a negative photoresist,meaning that portions of the photoresist exposed to radiation will berespectively soluble or insoluble to photoresist developer applied tothe photoresist after the pattern is written into the photoresist. Thechemical composition of the photoresist determines whether thephotoresist will be a positive photoresist or a negative photoresist.For example, the photoresist may include at least one ofdiazonaphthoquinone, a phenol formaldehyde resin, poly(methylmethacrylate), poly(methyl glutarimide), and SU-8. The pattern of thephotoresist may be transferred to a surface of the substrate 140 to formthe electronic circuitry.

The processing system 100 may further include a pair of supports 122 anda pair of rails 124. The pair of supports 122 may be disposed on theslab 120. The slab 120 and the pair of supports 122 may be a singlepiece of material. The pair of rails 124 may be supported by the pair ofsupports 122. The two or more stages 130 may move along the rails 124 inthe x-direction. In one embodiment, the pair of rails 124 is linear. Inother embodiments, the track 124 may have a non-linear shape. An encoder126 may be coupled to each stage 130 or rail 124 in order to provideinformation to a controller (not shown) of the position of the stage 130relative to the rail 124.

The processing apparatus 160 may include a support 162 and a processingunit 164. The support 162 may be disposed on the slab 120. The support162 may include an opening 166 for the two or more stages 130 to passunder the processing unit 164. The processing unit 164 may be supportedby the support 162. In one embodiment, the processing unit 164 is apattern generator configured to expose a photoresist disposed on thesubstrate 140 using a photolithography process. In some embodiments, thepattern generator may be configured to perform a maskless lithographyprocess. The processing unit 164 may include a plurality of imageprojection systems (shown in FIG. 3) disposed in a case 165. Theprocessing apparatus 160 may be utilized to perform maskless directpatterning. During operation, one of the two or more stages 130 moves inthe x-direction from a loading position, as shown in FIG. 1, to aprocessing position below the processing unit 164. The stages 130 may belifted by a plurality of air bearings 202 (shown in FIG. 2) when movingalong the pair of rails 124. A plurality of vertical guide air bearings(not shown) may be coupled to each stage 130 and positioned adjacent aninner wall 128 of each support 122 in order to stabilize the movement ofthe stage 130. A track 150 may be disposed between stages 130 and therails 124 so that the stages 130 may also be moved in the y-directionalong the track 150 for processing and/or indexing the substrate 140,particularly below the processing unit 164 while processing thesubstrate 140.

FIG. 2 is a cross-sectional side view of the processing system 100 ofFIG. 1, according to one embodiment. As discussed above, each stage 130includes a plurality of air bearings 202 for lifting the stage 130. Eachstage 130 may also include an actuator, such as a motor, for moving thestage 130 along the rails 124. The two or more stages 130 and theprocessing apparatus 160 may be enclosed by an enclosure (not shown) inorder to provide temperature and pressure control.

The system 100 also includes a controller 190. The controller 190 isgenerally designed to facilitate the control and automation of theprocessing techniques described herein. The controller 190 may becoupled to or in communication with one or more of the processingapparatus 160, the stages 130, and the encoder 126. The processingapparatus 160 and the stages 130 may provide information to thecontroller 190 regarding the substrate processing and the substratealigning. For example, the processing apparatus 160 may provideinformation to the controller 190 to alert the controller 190 thatsubstrate processing has been completed.

The controller 190 may include a central processing unit (CPU) 192,memory 194, and support circuits (or I/O) 196. The CPU may be one of anyform of computer processors that are used in industrial settings forcontrolling various processes and hardware (e.g., pattern generators,motors, and other hardware) and monitor the processes (e.g., processingtime and substrate position). The memory 194 is connected to the CPU192, and may be one or more of a readily available memory, such asrandom access memory (RAM), read only memory (ROM), floppy disk, harddisk, or any other form of digital storage, local or remote. Softwareinstructions and data can be coded and stored within the memory 194 forinstructing the CPU 192. The support circuits 196 are also connected tothe CPU for supporting the processor in a conventional manner. Thesupport circuits may include conventional cache, power supplies, clockcircuits, input/output circuitry, subsystems, and the like. A program(or computer instructions) readable by the controller determines whichtasks are performable on a substrate. The program may be softwarereadable by the controller and may include code to monitor and control,for example, the processing time and substrate position.

FIG. 3 is a perspective view of a plurality of image projection systems301 according to one embodiment. As shown in FIG. 3, each imageprojection system 301 produces a plurality of write beams 302 onto asurface 304 of the substrate 140. As the substrate 140 moves in thex-direction and the y-direction, the entire surface 304 may be patternedby the write beams 302. The number of image projection systems 301 mayvary based on the size of the substrate 140 and/or the speed of thestage 130.

FIG. 4 is a perspective schematic view of one image projection system301 of the plurality of image projection systems 301 of FIG. 3 accordingto one embodiment. The image projection system 301 may one or more lightsources 402, an aperture 404, a lens 406, a mirror 408, multiple digitalmicromirror device (DMD) assembly 410, a light dump 412, a camera 414,and a projection lens 416. The light source 402 may be an LED or alaser. The light source 402 may be capable of producing a light having apredetermined wavelength. In one embodiment, the predeterminedwavelength is in the blue or near ultraviolet (UV) range, such as lessthan about 450 nm. The mirror 408 may be a spherical or other suitablemirror. The projection lens 416 may be a 10× objective lens. Theprojection lens 416 may alternatively have other magnification.

During operation, a beam 403 having a predetermined wavelength, such asa wavelength in the blue range, is produced by the light source 402. Thebeam 403 is reflected to the multiple DMD assembly 410 by the mirror408. The DMD assembly 410 forms a plurality of write beams 302, andreflects the plurality of write beams 302 to the surface 304 of thesubstrate. The plurality of write beams 302 patterns the surface of thesubstrate by exposing areas of the substrate. Pixels (not shown) areformed in the exposed areas. The multiple DMD assembly 410 is configuredto double the number of pixels formed by the write beams 302 provided tothe surface 304 of the substrate compared to the number of pixelsprovided from a conventional image projection device with a single DMDbecause the number of write beams provided by the multiple DMD assembly410 is greater than the number of write beams produced by a single DMD.

FIG. 5 is a perspective view a multiple DMD assembly 500 which may bethe same as the multiple DMD assembly 410 (depicted in FIG. 4),according to one embodiment. The multiple DMD assembly 500 may includeone or more polarizing beam splitting cubes 504, a plurality of quarterwave plates 506, 508, and a plurality of DMDs 510, 512. The polarizingbeam splitting cube 504 includes a light altering device 514 and aplurality of openings 516. In the embodiment shown in FIG. 5, the lightaltering device 514 is an interface 514. For example, the interface 514may be in the form of a diagonal prism frame. The polarizing beamsplitting cube 504 is configured to split incoming light 403 from thelight source 402 into an s-polarization beam 520 and a p-polarizationbeam 522. The incoming light 403 is transmitted to the diagonal prismframe 514. The diagonal prism frame 514 splits the incoming light 403into the s-polarization beam 520 that is transmitted through thediagonal prism frame 514 and the p-polarization beam 522 that isreflected off the diagonal prism frame 514.

The first quarter phase plate 506 is disposed in one of the openings 516of the polarizing beam splitting cube 504. The s-polarization beam 520passes through the first quarter phase plate 506. The first quarterphase plate 506 is configured to change the polarization of thes-polarization beam 520 by a quarter phase. The first DMD 510 isdisposed opposite the first quarter phase plate 506. The first DMD 510includes a plurality of mirrors 550. The number of mirrors 550 maycorrespond to the resolution of the resolution of the projected image.

In one embodiment, the first DMD 510 includes 1920×1080 mirrors 550,which represent the number of pixels of a high definition television orflat panel display. The plurality of mirrors 550 in the first DMD 510may be controlled individually. Each mirror 550 of the plurality ofmirrors 550 of the first DMD 510 may be set to an “on” position or an“off” position. When the s-polarization beam 520 reaches the mirrors 550of the first DMD 510, the mirrors 550 that are set at the “on” positionreflect the s-polarization beam 520 back towards the diagonal prismframe 514. The mirrors 550 that are set to the “off” position reflectthe s-polarization beam to the light dump 412 rather than back towardsthe diagonal prism frame 514. The first DMD 510 is configured to reflectthe s-polarization beam 520, such that the s-polarization beam 520passes back through the first quarter phase plate 506. The first quarterphase plate 506 changes the polarization of the s-polarization beam 520by an additional quarter phase, such that the first quarter phase plate506 changes the polarization of the s-polarization beam 520 by a totalof a half phase. Thus, after the s-polarization beam 520 passes throughthe quarter phase plate 506 a second time, the s-polarization beam 520changes polarization to a p′-polarization beam 523. Therefore, ratherthan passing through the diagonal prism frame 514, the p′-polarizationbeam 523 reflects off the diagonal prism frame 514 towards the image outopening.

The second quarter phase plate 508 is disposed in one of the openings516 of the polarizing beam splitting cube 504, for example, an openingadjacent to the first quarter phase plate 506. The p-polarization beam522 passes through the second quarter phase plate 508. The secondquarter phase plate 508 is configured to change the polarization of thep-polarization beam 522 by a quarter phase. The second DMD 512 isdisposed opposite the second quarter phase plate 508. The second DMD 512is constructed similarly to the first DMD 510.

When the p-polarization beam 522 reaches the mirrors 552 of the secondDMD 512, the mirrors 552 that are at the “on” position reflect thep-polarization beam 522 back towards the diagonal prism frame 514. Themirrors 552 that are at the “off” position reflect the p-polarizationbeam to the light dump 412 rather than back towards the diagonal prismframe 514. The second DMD 512 is configured to reflect thep-polarization beam 522, such that the p-polarization beam 522 passesback through the second quarter phase plate 508. The second quarterphase plate 508 changes the polarization of the p-polarization 522 by anadditional quarter phase, such that the second quarter phase plate 508changes the polarization of the p-polarization beam 522 by a total of ahalf phase. Thus, after the p-polarization beam 522 passes through thequarter phase plate 508 a second time, the p-polarization beam 522changes polarization to an s′-polarization beam 524. Therefore, ratherthan reflecting off the diagonal prism frame 514, the s′-polarizationbeam 524 passes through the diagonal prism frame 514 towards the imageout opening, such that a plurality of superimposed images is transmittedfrom the multiple DMD assembly onto the substrate 140 to expose anunderlying layer in areas on the surface of the substrate 140.

The multiple DMD assembly 500 further includes adjustment mechanisms526, 528 coupled to each DMD 510, 512. The adjustment mechanisms 526,528 allow the user to adjust the position of the DMDs 510, 512 such thatmultiple DMD assembly 500 projects an image out that contains aplurality of write beams onto the substrate 140. The plurality ofsuperimposed images forms approximately twice the amount of pixels asthat formed by a single DMD because twice the amount of write beamsexposes twice the number of areas on the surface of the substrate. Inone embodiment, the write beams provided by the multiple DMD assembly500 may be patterned as an offset grid of write beams. The offset gridof write beams results in twice the amount of pixels formed by themultiple DMD assembly 500. Therefore, the multiple DMD assembly 500increases resolution while cutting the cost of adding additional imageprojection devices.

FIG. 6 illustrates a method 600 of producing an image on a substrateusing a multiple DMD assembly, such as the DMD assembly 508 of FIG. 5.The method 600 begins at block 602 by providing a single beam of lightto the multiple DMD assembly. A light source provides the single beam oflight to the multiple DMD assembly. For example, the light source may bethe light source 402, which may be capable of producing light having apredetermined wavelength. In one embodiment, the predeterminedwavelength is in the blue or near ultraviolet (UV) range, such as lessthan about 450 nm.

At block 604, the multiple DMD assembly splits the single beam of lightinto an s-polarization beam and a p-polarization beam. For example, inthe multiple DMD assembly 500 shown in FIG. 5, polarizing beam splittingcube 504 splits the single beam of light into an s-polarization beam 520and a p-polarization beam 522.

At block 606, the multiple DMD assembly reflects the s-polarization beamand the p-polarization beam such that the multiple DMD assembly producesa plurality of superimposed write beams on the substrate. In themultiple DMD assembly 500 shown in FIG. 5, the s-polarization passesthrough a quarter wave plate and reflects off a first DMD. The reflecteds-polarization beam passes through the quarter wave plate a second time,such that the s-polarization beam undergoes a total phase change of ahalf phase. Thus, the s-polarization beam is now a p′-polarization beam.The reflected p-polarization beam passes through a second quarter waveplate and reflects off a second DMD. Similar to the s-polarization beam,the p-polarization beam passes through the second quarter wave platetwice, such that the p-polarization beam undergoes a total phase changeof a half phase. Thus, the p-polarization beam is now an s′-polarizationbeam. The p′-polarization beam is transmitted through a diagonal prismframe in the polarizing beam splitting cube and the s′-polarization beamis reflected off the diagonal prism frame such that a plurality ofsuperimposed write beams is transmitted from the multiple DMD assemblyonto a substrate. The plurality of superimposed write beams exposes anunderlying layer in areas of the substrate, such that approximatelytwice the amount of pixels are formed on the substrate as compared tothe number of pixels formed by a single DMD.

FIG. 7 illustrates a multiple DMD assembly 700, according to oneembodiment. The multiple DMD assembly 700 may include a first lightaltering device 704, a second light altering device 706, a plurality ofDMDs 708, 710, and a turning mirror 716. The first light altering device704 is configured to split incoming light 718 from the light source 402into an s-polarization beam 720 and a p-polarization beam 722. Forexample, the first light altering device 704 may be a 45° Wollanstonprism such that the s-polarization beam 720 and the p-polarization beam722 diverge from the first light altering device 704 at an angle ofabout 45 degrees.

The first DMD 708 is positioned relative to the first light alteringdevice 704, such that the s-polarization beam 720 contacts the first DMD708 after the s-polarization beam 720 diverges from the first lightaltering device 704. The first DMD 708 includes a plurality of mirrors750. The number of mirrors 750 may correspond to the resolution of theresolution of the projected image. In one embodiment, the first DMD 708includes 1920×1080 mirrors, which represent the number of pixels of ahigh definition television or flat panel display. The plurality ofmirrors 750 in the first DMD 708 may be controlled individually. Eachmirror 750 of the plurality of mirrors 750 of the first DMD 708 may beat an “on” position or an “off” position. When the s-polarization beam720 reaches the mirrors 750 of the first DMD 708, the mirrors 750 thatare at the “on” position reflect the s-polarization beam 720 backtowards the turning mirror 716. The mirrors 750 that are at the “off”position reflect the s-polarization beam 720 to the light dump 412.

The second DMD 710 is positioned opposite the first DMD 708, andrelative to the first light altering device 704, such that thep-polarization beam 722 contacts the second DMD 710 when thep-polarization beam 722 diverges from the first light altering device704. The second DMD 710 is similarly constructed as the first DMD 708.

When the p-polarization beam 722 reaches the second DMD 710, the mirrors752 that are at the “on” position reflect the p-polarization beam 722 tothe turning mirror 716. The mirrors 752 that are at the “off” positionreflect the p-polarization beam to the light dump 412.

The turning mirror 716 is configured to reflect the s-polarization beam720 and the p-polarization beam 722 towards the second light alteringdevice 706. The turning mirror 716 is shaped and positioned such thatthe s-polarization beam 720 and the p-polarization beam 722 enter thesecond light altering device 706 at an angle. For example, in oneembodiment, the angle may be about 21 degrees.

The second light altering device 706 in configured to change thedirection of the incoming s-polarization beam and the p-polarizationbeam. The multiple DMD assembly 700 projects an image out that includesa plurality of superimposed write beams onto a substrate. The pluralityof superimposed write beams exposes the underlying layer in areas on thesurface of the substrate 140. Pixels are formed in the exposed areas onthe surface of the substrate. The plurality of superimposed write beamsresults in approximately twice the amount of pixels formed on thesurface of the substrate 140 as comparted to the number of pixels formedby a single DMD. In one embodiment, the plurality of write beamstransmitted by the multiple DMD assembly 700 may be an offset grid ofwrite beams. The offset grid of write beams allows twice the amount ofpixels to be formed on the surface of the substrate 140. Therefore, themultiple DMD assembly 700 increases resolution while cutting the cost ofadding additional image projection devices.

FIG. 8 illustrates a method 800 of producing an image on a substrateusing the multiple DMD assembly of FIG. 7. The method 800 begins atblock 802 by providing a single beam of light to the multiple DMDassembly. A light source provides the single beam of light to themultiple DMD assembly. For example, the light source may be light source402, which may be capable of producing light having a predeterminedwavelength. In one embodiment, the predetermined wavelength is in theblue or near ultraviolet (UV) range, such as less than about 450 nm.

At block 804, the multiple DMD assembly splits the single beam of lightinto an s-polarization beam and a p-polarization beam. For example, inthe multiple DMD assembly 700 shown in FIG. 7, the first light alteringdevice 704 splits the single beam of light into an s-polarization beam720 and a p-polarization beam 722.

At block 806, the multiple DMD assembly reflects the s-polarization beamand the p-polarization beam such that the multiple DMD assembly producesa plurality of superimposed write beams on the substrate. In themultiple DMD assembly 700 shown in FIG. 7, the polarization beamsdiverge from the first light altering device 704. The s-polarizationbeam is transmitted to the first DMD assembly. The s-polarization beamreflects off the mirrors of the first DMD assembly. The p-polarizationbeam is transmitted to the second DMD assembly. The p-polarization beamreflects off the mirrors of the second DMD assembly. The reflecteds-polarization beam and the reflected p-polarization beam aretransmitted to a turning mirror. The turning mirror reflects thepolarization beams at an angle towards a second light altering device.The second light altering device reflects the s-polarization beam andthe p-polarization beam such that a plurality of superimposed writebeams is transmitted from the multiple DMD assembly. The plurality ofsuperimposed write beams expose the underlying layer in areas on thesurface of the substrate such that approximately twice the amount ofpixels are formed on the surface of the substrate as compared to thenumber of pixels formed by a single DMD.

FIG. 9 illustrates an image projection system 900, according to oneembodiment. The image projection system 900 includes a plurality oflight sources 902, 904, a plurality of mirror cubes 906, 908, and alight altering device 910. The first light source 902 is configured toprovide a light beam to first mirror cube 906. In the embodiment shownin FIG. 9, the first light source 902 provides a p-polarization beam 916to the first mirror cube. The first light source 902 may be an LED or alaser. The first light source 902 may be capable of producing a lighthaving a predetermined wavelength. In one embodiment, the predeterminedwavelength is in the blue or near UV range, such as less than about 450nm. The first mirror cube 906 includes a first DMD 912. The first DMD912 includes a plurality of mirrors 950. The number of mirrors 950 maycorrespond to the resolution of the resolution of the projected image.

The first DMD 912 includes 1920×1080 mirrors, which represent the numberof pixels of a high definition television or flat panel display. Theplurality of mirrors 950 in the first DMD 912 may be controlledindividually. When the p-polarization beam 916 reaches the mirrors 950of the first DMD 912, the mirrors 950 that are at an “on” positionreflect the p-polarization beam 916 out of the first mirror cube 906towards the light altering device 910. The mirrors 950 that are at the“off” position reflect the p-polarization beam 916 to a heat sink. Thefirst DMD 912 is configured to reflect the p-polarization beam 916, suchthat the p-polarization beam 916 passes out of the first mirror cube906.

The second light source 904 is configured to provide a light beam to thesecond mirror cube 908. In the embodiment shown in FIG. 9, the secondlight source 904 provides an s-polarization beam 918 to the secondmirror cube 908. The second light source 904 is similar to the firstlight source 902. The second mirror cube 908 includes a second DMD 914.The second DMD 914 is similarly constructed as the first DMD 912. Whenthe s-polarization beam 918 reaches the mirrors 952 of the second DMD914, the mirrors 952 that are at an “on” position reflect thes-polarization beam 918 out of the second mirror cube 908 and towardsthe light altering device 910. The mirrors 952 that are at the “off”position reflect the s-polarization beam 918 to a heat sink. The secondDMD 914 is configured to reflect the s-polarization beam 918, such thatthe s-polarization beam 918 passes out of the second mirror cube 908.

The p-polarization beam 916 and the s-polarization beam 918 aretransmitted form the respective mirror cubes 906, 908 to the lightaltering device 910. In one embodiment, the light altering device 910may be a 50/50 beam splitter. The light altering device 910 isconfigured to transmit the p-polarization beam through the 50/50 beamsplitter. Additionally, the light altering device 910 is configured toreflect the s-polarization beam 918 off the 50/50 beam splitter.

As a result, the image projection system 900 projects an image out thatincludes a plurality of superimposed write beams onto a substrate. Theplurality of superimposed light beams exposes the underlying layer inareas on the surface of the substrate such that approximately twice theamount of pixels are formed on the surface of the substrate as comparedto the number of pixels formed by a single DMD. In one embodiment, theplurality of write beams transmitted from the multiple DMD assembly 900may be an offset grid of light beams. The offset grid of light beamsresults in twice the amount of pixels formed on the substrate.Therefore, the multiple DMD assembly 900 increases resolution whilecutting the cost of adding additional image projection devices.

In the arrangement depicted in FIG. 9, the path lengths for thes-polarization beam and the p-polarization beam are about the same.

FIG. 10 illustrates a method 1000 of producing an image on a substrateusing the image projection device of FIG. 9. The method 1000 begins atblock 1002 by providing a first beam of light to a first DMD, whereinthe first beam of light is an s-polarization beam.

At block 1004, a second light source provides a second beam of light toa second DMD, wherein the second beam of light is a p-polarization beam.The first DMD reflects the s-polarization beam towards a light alteringdevice. The second DMD reflects the p-polarization beam towards thelight altering device.

At block 1006, the light altering device transmits the s-polarizationbeam and the p-polarization beam out of the image projection device suchthat a plurality of superimposed write beams is transmitted onto asubstrate. In one embodiment, the light altering device may be a 50/50beam splitter. The p-polarization beam is transmitted through the 50/50beam splitter and out of the image projection system. The s-polarizationbeam is reflected off the 50/50 beam splitter and out of the imageprojection system, such that a plurality of superimposed write beams istransmitted from the image projection device. The plurality ofsuperimposed write beams exposes the underlying layer on areas on thesurface of the substrate such that approximately twice the amount ofpixels are formed on the surface of the substrate as compared to thenumber of pixels formed by a single DMD.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

What is claimed is:
 1. A method for producing an image on a substrate,comprising: providing a p-polarization beam; providing an s-polarizationbeam; providing the p-polarization beam to a first mirror cube having afirst digital micromirror device (DMD) configured to generate a firstimage; providing the s-polarization beam to a second mirror cube havinga second DMD configured to generate a second image; and reflecting thep-polarization beam off the first DMD and reflecting the s-polarizationbeam off the second DMD such that the p-polarization beam and thes-polarization beam are reflected towards a light altering deviceconfigured to produce a plurality of superimposed images on aphotoresist layer of the substrate.
 2. The method of claim 1, whereinthe plurality of superimposed images exposes an underlying layer on thesubstrate.
 3. The method of claim 2, wherein exposing the underlyinglayer on the substrate forms pixels.
 4. The method of claim 1, whereinthe plurality of superimposed images forms a grid like pattern.
 5. Themethod of claim 4, wherein the grid like pattern is offset.
 6. Themethod of claim 1, wherein the first DMD or the second DMD comprises aplurality of mirrors having an array of 1,920 mirrors x 1,080 mirrors.7. The method of claim 1, wherein the first DMD comprises a plurality ofmirrors, and wherein the method further comprises: reflecting thep-polarization beam towards the light altering device when the pluralityof mirrors is in a first position; adjusting the plurality of mirrorsfrom the first position to a second position; and reflecting thep-polarization beam towards a heat sink when the plurality of mirrors isin the second position.
 8. The method of claim 1, wherein the second DMDcomprises a plurality of mirrors, and wherein the method furthercomprises: reflecting the s-polarization beam towards the light alteringdevice when the plurality of mirrors is in a first position; adjustingthe plurality of mirrors from the first position to a second position;and reflecting the s-polarization beam towards a heat sink when theplurality of mirrors is in the second position.
 9. A method forproducing an image on a substrate, comprising: providing ap-polarization beam to a first mirror cube having a first digitalmicromirror device (DMD) configured to generate a first image, from afirst light source; providing an s-polarization beam to a second mirrorcube having a second DMD configured to generate a second image, from asecond light source; and reflecting the p-polarization beam off thefirst DMD and reflecting the s-polarization beam off the second DMD suchthat the p-polarization beam and the s-polarization beam are reflectedtowards a light altering device configured to produce a plurality ofsuperimposed images on a photoresist layer of the substrate.
 10. Themethod of claim 9, wherein the first light source or the second lightsource is a light emitting diode (LED) or a laser.
 11. The method ofclaim 9, wherein the plurality of superimposed images exposes anunderlying layer on the substrate.
 12. The method of claim 9, whereinthe second DMD comprises a plurality of mirrors, and wherein the methodfurther comprises: reflecting the s-polarization beam towards the lightaltering device when the plurality of mirrors is in a first position;adjusting the plurality of mirrors from the first position to a secondposition; and reflecting the s-polarization beam towards a heat sinkwhen the plurality of mirrors is in the second position.
 13. The methodof claim 9, wherein the plurality of superimposed images forms a gridlike pattern.
 14. The method of claim 9, wherein the first DMD or thesecond DMD comprises a plurality of mirrors having an array of 1,920mirrors×1,080 mirrors.
 15. The method of claim 9, wherein the first DMDcomprises a plurality of mirrors, and wherein the method furthercomprises: reflecting the p-polarization beam towards the light alteringdevice when the plurality of mirrors is in a first position; adjustingthe plurality of mirrors from the first position to a second position;and reflecting the p-polarization beam towards a heat sink when theplurality of mirrors is in the second position.
 16. The method of claim9, wherein the second DMD comprises a plurality of mirrors, and whereinthe method further comprises: reflecting the s-polarization beam towardsthe light altering device when the plurality of mirrors is in a firstposition; adjusting the plurality of mirrors from the first position toa second position; and reflecting the s-polarization beam towards a heatsink when the plurality of mirrors is in the second position.